Nearly half of all pregnancies in the United States are unintended. Thus, there is a critical need for fertility regulation that fits the needs of women and men throughout their reproductive lives. The Contraceptive Discovery and Development Branch (CDDB) support research in the synthesis and testing of a broad spectrum of male and female contraceptive agents. Successful development of new contraceptive methods for men and women has been a goal for many decades. From the inception of this program in1976, the CDDB has had a continuing need for the discovery chemistry and the subsequent development of the anti-fertility agents. The Medicinal Chemistry Facility (MCF) fulfills a unique role in bridging the discovery of contraceptive targets to the development and approval of the contraceptive drug. To this end, the research at the MCF will encompass discovery and optimization of small molecule antagonist or agonists of protein targets as anti-fertility agents. In addition, the MCF has an important role in enriching and providing pre-clinical antifertility drug pipeline. The Scope of this contract is for the Medicinal Chemistry Facility to carry out integrated drug discovery and optimization of anti-fertility agents on protein targets specific to male or female reproductive system.